Block copolymer

ABSTRACT

The present application provides a block copolymer and uses thereof. The block copolymer of the present application exhibits an excellent self-assembling property or phase separation property, can be provided with a variety of required functions without constraint and, especially, etching selectivity can be secured, making the block copolymer effectively applicable to such uses as pattern formation.

FIELD

This application claims priority to and the benefit of Korean PatentApplication No. 2014-0131964, filed on Sep. 30, 2014, and No.2015-0079483, filed on Jun. 4, 2015, the disclosure of which isincorporated herein by reference in its entirety.

The present application relates to a block copolymer and uses thereof.

BACKGROUND

The block copolymer has a molecular structure in which polymer blocks,each with a distinct chemical structure, are connected to one another bycovalent bonds. The block copolymer can be constructed in a regularlyarranged structure—such as a sphere, a cylinder, and a lamella—throughphase separation. The structure that is formed as the result of theself-assembly phenomenon of a block copolymer has a domain whose sizecan be adjusted over a wide range, and it can be constructed in variousforms which can be applied to the production of a variety ofnext-generation nanodevices, magnetic storage media, and patterns (bylithography or the like): to be specific, the production of high-densitymagnetic recording media, nanowires, quantum dots, metal dots or thelike.

Material properties of a block copolymer required for use in the aboveproduction of patterns include an etching selectivity plus aself-assembling property. That is, the fabrication of a mask for theproduction of a pattern may require a process of selectively removingany one block among the blocks—that are chemically different from oneanother—of a self-assembled block copolymer; in the case that theetching selectivity among the blocks is not secured during the aboveprocess, it is difficult for the block copolymer to be used in theproduction of a pattern.

DESCRIPTION Object

The present application provides block copolymers and uses thereof.

Solution

Unless specifically indicated otherwise, the term “an alkyl group” inthe present specification may refer to an alkyl group with 1 to 20carbons, 1 to 16 carbons, 1 to 12 carbons, 1 to 8 carbons or 1 to 4carbons. The above alkyl group may be a linear-type, a branched-type ora ring-type, and it may be optionally substituted in part by one or moresubstituents.

Unless specifically indicated otherwise, the term “an alkoxy group” inthe present specification may refer to an alkoxy group with 1 to 20carbons, 1 to 16 carbons, 1 to 12 carbons, 1 to 8 carbons or 1 to 4carbons. The above alkoxy group may be a linear-type, a branched-type ora ring-type, and it may be optionally substituted in part by one or moresubstituents.

Unless specifically indicated otherwise, the term “an alkenyl group” or“an alkynyl group” in the present specification may refer to an alkenylgroup or alkynyl group with 2 to 20 carbons, 2 to 16 carbons, 2 to 12carbons, 2 to 8 carbons or 2 to 4 carbons. The above alkenyl group oralkynyl group may be a linear-type, a branched-type or a ring-type, andit may be optionally substituted in part by one or more substituents.

Unless specifically indicated otherwise, the term “an alkylene group” inthe present specification may refer to an alkylene group with 1 to 20carbons, 1 to 16 carbons, 1 to 12 carbons, 1 to 8 carbons or 1 to 4carbons. The above alkylene group may be a linear-type, a branched-typeor a ring-type, and it may be optionally substituted in part by one ormore substituents.

Unless specifically indicated otherwise, the terms “an alkenylene group”or “an alkynylene group” in the present specification may refer to analkenylene group or alkynylene group with 2 to 20 carbons, 2 to 16carbons, 2 to 12 carbons, 2 to 8 carbons or 2 to 4 carbons. The abovealkenylene group or alkynylene group may be a linear-type, abranched-type or a ring-type, and it may be optionally substituted inpart by one or more substituents.

Unless specifically indicated otherwise, the term “an aryl group” or “anarylene group” in the present specification may refer to a monovalent ordivalent residue that is derived from a compound that has a benzene ringstructure or a structure in which two or more benzene rings areconnected to one another (either by sharing one or two carbon atoms orby any linker) or from a derivative of the above compound. Unlessspecifically indicated otherwise, the above aryl group or arylene groupmay refer to an aryl group with, for example, 6 to 30 carbons, 6 to 25carbons, 6 to 21 carbons, 6 to 18 carbons, or 6 to 13 carbons.

In the present application, the term “an aromatic structure” may referto the above aryl group or arylene group.

In the present specification, the term “an alicyclic ring structure”refers to, unless specifically indicated otherwise, a ring-typehydrocarbon atom structure other than an aromatic ring structure. Unlessspecifically indicated otherwise, the above alicyclic ring structure mayrefer to an alicyclic ring structure with, for example, 3 to 30 carbons,3 to 25 carbons, 3 to 21 carbons, 3 to 18 carbons, or 3 to 13 carbons.

In the present application, the term “a single bond” may refer to thecase in which a particular atom is not present in the correspondingarea. For example, when B denotes a single bond in the structure that isrepresented by A-B-C, it may be assumed that there is no particular atompresent in the region that is marked as B, resulting in a directconnection between A and C to form the structure that is represented byA-C.

In the present application, examples of the substituent that may beoptionally substituted for a part or parts of an alkyl group, an alkenylgroup, an alkynyl group, an alkylene group, an alkenylene group, analkynylene group, an alkoxy group, an aryl group, an arylene group, achain, an aromatic structure or the like may include, but are notlimited to, a hydroxyl group, a halogen atom, a carboxyl group, aglycidyl group, an acryloyl group, a methacryloyl group, an acryloyloxygroup, a methacryloyloxy group, a thiol group, an alkyl group, analkenyl group, an alkynyl group, an alkylene group, an alkenylene group,an alkynylene group, an alkoxy group, an aryl group and the like.

The block copolymer of the present application may contain a block(which may be referred to as the block 1 hereinafter) that contains astructural unit represented by the following Structural Formula 1. Theblock 1 may either consist only of the structural unit represented bythe following Structural Formula 1 or contain another structural unit inaddition to the above structural unit represented by Structural Formula1.

In Structural Formula 1, R represents a hydrogen atom or an alkyl group;X represents a single bond, an oxygen atom, a sulfur atom, —S(═O)₂—, acarbonyl group, an alkylene group, an alkenylene group, an alkynylenegroup, —C(═O)—X₁— or —X₁—C(═O)—, where the X₁ represents an oxygen atom,a sulfur atom, —S(═O)₂—, an alkylene group, an alkenylene group or analkynylene group; and Y represents a monovalent substituent thatincludes a ring structure to which a chain containing 8 or morechain-forming atoms is connected.

In another embodiment, the X of Structural Formula 1 may represent asingle bond, an oxygen atom, a carbonyl group, —C(═O)—O—, —O—C(═O)— or—C(═O)—O—, although it is not limited thereto.

The monovalent substituent represented by the Y of Structural Formula 1includes a chain structure constructed by at least 8 chain-formingatoms.

In the present application, the term “a chain-forming atom” refers to anatom that forms a linear structure of a predetermined chain. The chainmay be a linear-type or a branched-type, but the number of chain-formingatoms is counted only by the number of atoms that form the longestlinear chain, and the other atoms that are bonded to the abovechain-forming atoms (e.g. when the chain-forming atom is a carbon atom,the hydrogen atom or the like that is bonded to the carbon atom) are nottaken into account. In the case of a branched-type chain, the number ofchain-forming atoms may be counted by the number of chain-forming atomsthat form the longest chain. For example, when the chain is an n-pentylgroup, all of the chain-forming atoms are carbon and the number of thechain-forming atoms is five, and when the above chain is a2-methylpentyl group, all of the chain-forming atoms are carbon and thenumber of the chain-forming atoms is 5. Examples of a chain-forming atommay include carbon, oxygen, sulfur, and nitrogen; a suitablechain-forming atom may be any one of carbon, oxygen and nitrogen, or anyone of carbon and oxygen. The number of chain-forming atoms in a chainmay be 8 or more, 9 or more, 10 or more, 11 or more, or 12 or more. Thenumber of chain-forming atoms in a chain may also be 30 or less, 25 orless, 20 or less, or 16 or less.

The structural unit represented by Structural Formula 1 can provide anexcellent self-assembling property to the above block copolymer to whichit belongs.

In one embodiment, the aforementioned chain may be a linear hydrocarbonchain such as a linear alkyl group. In such a case, the alkyl group maybe an alkyl group with 8 or more carbons, 8 to 30 carbons, 8 to 25carbons, 8 to 20 carbons, or 8 to 16 carbons. One or more carbon atomsin the above alkyl group may each be substituted optionally by an oxygenatom, and at least one hydrogen atom in the alkyl group may each besubstituted optionally by another substituent.

In Structural Formula 1, the Y may include a ring structure, and theabove chain may be connected to the ring structure. Such a ringstructure may contribute to the further improvement of a self-assemblingproperty and the like of the block copolymer that is made of the monomerto which it belongs. The ring structure may be an aromatic structure oran alicyclic structure.

The above chain may be connected to the above ring structure eitherdirectly or by a linker. Examples of the linker may include an oxygenatom, a sulfur atom, —NR₁—, —S(═O)₂—, a carbonyl group, an alkylenegroup, an alkenylene group, an alkynylene group, —C(═O)—X₁— and—X₁—C(═O)—, where the R₁ may represent a hydrogen atom, an alkyl group,an alkenyl group, an alkynyl group, an alkoxy group or an aryl group,and the X₁ may represent a single bond, an oxygen atom, a sulfur atom,—NR₂—, —S(═O)₂—, an alkylene group, an alkenylene group or an alkynylenegroup, where the R₂ may represent a hydrogen atom, an alkyl group, analkenyl group, an alkynyl group, an alkoxy group, or an aryl group.Examples of a suitable linker may include an oxygen atom and a nitrogenatom. The above chain may be connected to an aromatic structure, forexample, by an oxygen atom or a nitrogen atom. In this case, the abovelinker may be an oxygen atom or —NR₁—(where R₁ represents a hydrogenatom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxygroup, or an aryl group).

In one embodiment, the Y of Structural Formula 1 may be represented bythe following Structural Formula 2.

—P-Q-Z  [Structural Formula 2]

In Structural Formula 2, P represents an arylene group; Q represents asingle bond, an oxygen atom or —NR₃—, where the R₃ represents a hydrogenatom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxygroup or an aryl group; and Z represents the aforementioned chain thatcontains 8 or more chain-forming atoms. When the Y of Structural Formula1 is the substituent represented by Structural Formula 2, the P ofStructural Formula 2 may be connected directly to the X of StructuralFormula 1.

A suitable embodiment of the P of Structural Formula 2 may include, butis not limited to, an arylene group with 6 to 12 carbons, for example, aphenylene group.

Suitable embodiments of the Q of Structural Formula 2 may include anoxygen atom and —NR₁—(where the R₁ represents a hydrogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an alkoxy group, or an arylgroup).

A suitable embodiment of the structural unit of Structural Formula 1 mayinclude a structural unit of Structural Formula 1, where the Rrepresents a hydrogen atom or an alkyl group (e.g. an alkyl group with 1to 4 carbons), the X represents —C(═O)—O—, and the Y is represented byStructural Formula 2, where the P represents a phenylene or an arylenegroup with 6 to 12 carbons, the Q represents an oxygen atom, and the Zrepresents the aforementioned chain containing 8 or more chain-formingatoms.

Therefore, a suitable illustrative structural unit of Structural Formula1 may include the structural unit represented by the followingStructural Formula 3.

In Structural Formula 3, R represents a hydrogen atom or an alkyl groupwith 1 to 4 carbon atoms, X represents —C(═O)—O—, P represents anarylene group with 6 to 12 carbons, Q represents an oxygen atom, and Zrepresents the aforementioned chain containing 8 or more chain-formingatoms.

In another embodiment, the structural unit (represented by StructuralFormula 1) of the block 1 may also be represented by the followingStructural Formula 4.

In Structural Formula 4, each of R₁ and R₂ independently represents ahydrogen atom or an alkyl group with 1 to 4 carbons; X represents asingle bond, an oxygen atom, a sulfur atom, —S(═O)₂—, a carbonyl group,an alkylene group, an alkenylene group, an alkynylene group, —C(═O)—X₁—or —X₁—C(═O)—, where the X₁ represents a single bond, an oxygen atom, asulfur atom, —S(═O)₂—, an alkylene group, an alkenylene group or analkynylene group; T represents a single bond or an arylene group; Qrepresents a single bond or a carbonyl group; and Y represents a chaincontaining 8 or more chain-forming atoms.

In Structural Formula 4, the X may represent a single bond, an oxygenatom, a carbonyl group, —C(═O)—O—, or —O—C(═O)—.

Specific examples of the chain of the Y of Structural Formula 4 may besimilar to what has been described of Structural Formula 1.

In another embodiment, an electronegativity of 3 or greater may beobserved in at least one chain-forming atom of a chain (with 8 or morechain-forming atoms) that is contained in any one of the structuralunits (represented by Structural Formulae 1, 3 and 4) of the block 1. Inanother embodiment, the electronegativity of the above atom(s) may be3.7 or less. Examples of the above atom(s) whose electronegativity is 3or greater may include, but are not limited to, a nitrogen atom and anoxygen atom.

The block 2 that is contained in a block copolymer together with theblock 1, which contains the above-described structural units, maycontain at least the structural unit that is represented by thefollowing Structural Formula 5.

In Structural Formula 5, X₂ represents a single bond, an oxygen atom, asulfur atom, —S(═O)₂—, an alkylene group, an alkenylene group, analkynylene group, —C(═O)—X₂— or —X₂—C(═O)—, where the X₂ represents asingle bond, an oxygen atom, a sulfur atom, —S(═O)₂—, an alkylene group,an alkenylene group or an alkynylene group; and each of R₁ to R₅independently represents a hydrogen atom, an alkyl group, a haloalkylgroup, an halogen atom or a photo crosslinkable functional group, wherethe number of a photo crosslinkable functional group(s) contained in thepositions marked as R₁ to R₅ is 1 or more.

The block 2 may consist only of the structural unit represented byStructural Formula 5 or contain one or more additional structural unitsthat will be described below in the present specification. When theblock 2 contains one or more additional structural units in addition tothe structural unit that is represented by Structural Formula 5, each ofthe structural units may form a separate subblock, or be randomlypositioned, in the block 2.

As described above, the structural unit that is represented byStructural Formula 5 contains at least one photo crosslinkablefunctional group. The block copolymer can be crosslinked by such a photocrosslinkable functional group before or after the formation of aself-assembled structure. When the crosslinking reaction is induced onlyin the block 2, the etching selectivity between the block 1 and theblock 2 can be improved.

As a photo crosslinkable functional group included in the unit ofStructural Formula 5, a functional group (hereinafter, referred to as aphoto-radical generating group) that can be crosslinked with generatingradicals when being irradiated with light or a functional group thatdoes not generate radicals however can be crosslinked in the presence ofradicals can be illustrated. In a case of the latter group, the blockcopolymer may be used in the process along with an appropriate radicalinitiator. As a photo crosslinkable functional group, benzoylphenoxygroup, alkenyloxycarbonyl group, (meth)acryloyl group or alkenyloxyalkylgroup may be illustrated, but is not limited thereto.

The structural unit represented by Structural Formula 5 may contain 1 ormore photo crosslinkable functional groups; for example, at least R₃ mayrepresent the above photo crosslinkable functional group.

The structural unit represented by Structural Formula 5 may contain 1 ormore, 2 or more, 3 or more, 4 or more or 5 or more halogen atoms (e.g. afluorine atom) in addition to the above photo crosslinkable functionalgroup(s). The number of the halogen atoms, such as a fluorine atom,contained in the structural unit may also be 10 or less, 9 or less, 8 orless, 7 or less, or 6 or less.

In the structural unit represented by Structural Formula 5, at leastone, 1 to 3 or 1 to 2 among the R₁ to R₅ may represent the abovecrosslinkable functional group(s).

In the structural unit represented by Structural Formula 5, 1 or more, 2or more, 3 or more, 4 or more or 5 or more halogen atoms may becontained in the positions marked as R₁ to R₅. The number of halogenatoms contained in the positions marked as R₁ to R₅ may also be 10 orless, 9 or less, 8 or less, 7 or less, or 6 or less.

When the block 2 contains an additional structural unit(s) in additionto the structural unit represented by Structural Formula 5, theproportion of the structural unit represented by Structural Formula 5may be adjusted to the range in which sufficient crosslinking reactionscan take place while the self-assembling property of the block copolymeris maintained. For example, the proportion of the above structural unit(represented by Structural Formula 5) in the block 2 may be about 0.1mol % to 5 mol %, 0.5 mol % to 5 mol %, 1 mol % to 5 mol %, 1.5 mol % to5 mol %, 1.5 mol % to 4 mol % or 1.5 mol % to 3 mol % based on the totalnumber of moles of the structural units in the block 2. Such aproportion may be adjusted depending on the types of the structuralunits or blocks contained in the block copolymer.

The block 2 of a block copolymer may contain another structural unit inaddition to the structural unit represented by the above StructuralFormula 5. In this case, the type of the structural unit that can beadditionally contained is not particularly limited.

For example, the block 2 may additionally contain a polyvinylpyrrolidonestructural unit, a polylactic acid structural unit, apoly(vinylpyridine) structural unit, a polystyrene structural unit suchas polystyrene and poly(trimethylsilyl styrene), a polyalkylene oxidestructural unit such as polyethylene oxide, a polybutadiene structuralunit, a polyisoprene structural unit, or a polyolefin structural unitsuch as polyethylene.

In one embodiment, the block 2 may contain a structural unit that has anaromatic structure with one or more halogen atoms, in addition to thestructural unit represented by Structural Formula 5.

For example, the above structural unit may be a structural unit that,unlike Structural Formula 5, does not contain a crosslinkable functionalgroup.

Such a second structural unit of the block 2 may be, for example, astructural unit that is represented by the following Structural Formula6.

In Structural Formula 6, B represents a monovalent substituent having anaromatic structure with one or more halogen atoms.

The block that contains a structural unit such as the above may providean excellent self-assembling property to the block copolymer to which itbelongs, by having an excellent interaction with other blocks such asthe block 1.

In Structural Formula 6, the aromatic structure may be, for example, anaromatic structure with 6 to 18 carbons or 6 to 12 carbons.

A fluorine atom or a chlorine atom may be exemplified and a fluorineatom may be preferably selected for the halogen atom(s) of StructuralFormula 6, although not limited thereto.

In one embodiment, the B of Structural Formula 6 may be a monovalentsubstituent having an aromatic structure that contains 6 to 12 carbonsand is substituted in part by 1 or more, 2 or more, 3 or more, 4 or moreor 5 or more halogen atoms. In the above description, there is noparticular limitation to the maximum number of the halogen atoms, andthere may be, for example, 10 or less, 9 or less, 8 or less, 7 or lessor 6 or less halogen atoms present.

In this case, the above structural unit (represented by StructuralFormula 6) may also be represented by the following Structural Formula7.

In Structural Formula 7, X₂ represents a single bond, an oxygen atom, asulfur atom, —S(═O)₂—, an alkylene group, an alkenylene group, analkynylene group, —C(═O)—X₁— or —X₁—C(═O)—, where the X₁ represents asingle bond, an oxygen atom, a sulfur atom, —S(═O)₂—, an alkylene group,an alkenylene group or an alkynylene group; and W represents an arylgroup with at least one halogen atom. The W may be an aryl group that issubstituted in part by at least one halogen atom; for example, it may bean aryl group with 6 to 12 carbons and substituted in part by 2 or more,3 or more, 4 or more or 5 or more halogen atoms.

In another embodiment, the above structural unit (represented byStructural Formula 6) may also be represented by the followingStructural Formula 8.

In Structural Formula 8, X₃ represents a single bond, an oxygen atom, asulfur atom, —S(═O)₂—, an alkylene group, an alkenylene group, analkynylene group, —C(═O)—X₁— or —X₁—C(═O)—, where the X₁ represents asingle bond, an oxygen atom, a sulfur atom, —S(═O)₂—, an alkylene group,an alkenylene group or an alkynylene group; and each of R_(a) to R_(e)independently represents a hydrogen atom, an alkyl group, a haloalkylgroup or a halogen atom, where the number of halogen atoms contained inthe positions marked as R_(a) to R_(e) is 1 or more.

In another embodiment, the X₃ of Structural Formula 8 may represent asingle bond, an oxygen atom, an alkylene group, —C(═O)—O—, or —O—C(═O)—.

In Structural Formula 8, each of R_(a) to R_(e) independently representsa hydrogen atom, an alkyl group, a haloalkyl group or a halogen atom,and there may be 1 or more, 2 or more, 3 or more, 4 or more or 5 or morehalogen atoms (e.g. a fluorine atom) contained in the positions markedas R_(a) to R_(e). The number of halogen atoms (e.g. a fluorine atom)contained in the positions marked as R_(a) to R_(e) may also be 10 orless, 9 or less, 8 or less, 7 or less, or 6 or less.

When the block 2 contains the above structural unit that has an aromaticstructure with one or more halogen atoms (e.g. a structural unit that isrepresented by any one of Structural Formulae 6 to 8) in addition to thestructural unit represented by Structural Formula 5, the ratio (DH/D5)of the number of moles (DH) of the above structural unit—that has anaromatic structure with one or more halogen atoms—to the number of moles(D5) of the structural unit represented by Structural Formula 5 may beabout 35 to 65, about 40 to 60, or about 40 to 50.

The block copolymer of the present application is a block copolymer madeup of one or more of each of the aforementioned block 1 and block 2. Itmay be a diblock copolymer made up only of the above two types ofblocks, or it may be a triblock or multiblock (with more than threetypes of blocks) copolymer which contains 2 or more of either one orboth of the block 1 and block 2 or contains another type of block(s) inaddition to the block 1 and block 2.

A block copolymer such as the above can inherently exhibit excellentphase separation or an excellent self-assembling property. The phaseseparation or self-assembling property can be further improved byselecting and combining blocks suitably and satisfying one or moreparameters that will be described below in the present specification.

A block copolymer contains 2 or more polymer chains which are connectedto one another by a covalent bond(s), and thus phase separation occurs.The block copolymer of the present application exhibits phase separationproperty and, if needed, can form a nanoscale structure throughmicrophase separation. The form and size of such a nanostructure may becontrolled by the size (molecular weight or the like) of the blockcopolymer or relative ratios among the blocks. Examples of a structurethat can be formed through phase separation may include a sphere, acylinder, a gyroid, a lamella and an inverted structure, and the blockcopolymer's ability to form such a structure may be referred to as“self-assembling”. The inventors recognized—among a variety of blockcopolymers described above in the present specification—a significantimprovement in the self-assembling property, which a block copolymerinherently possesses, in the block copolymers that satisfy at least oneamong the various parameters that will be described below in the presentspecification. The block copolymer of the present application maysatisfy any one of the parameters, or it may satisfy 2 or moreparameters at the same time. Especially, it was recognized that a blockcopolymer can be made to exhibit vertical orientation by satisfying oneor more suitable parameters. In the present application, the term“vertical orientation” refers to the direction in which a blockcopolymer is oriented and may indicate that the nanostructure formed bythe block copolymer is oriented vertically to the direction of asubstrate. Technology for controlling the self-assembled structure of ablock copolymer either horizontally or vertically on a variety ofsubstrates accounts for a remarkably large part in a practicalapplication of block copolymers. The orientation of a nanostructure in ablock copolymer film is generally determined by which block among theblocks constituting the block copolymer is exposed to the surface or inthe air. In general, the majority of substrates are polar and the air isnonpolar; therefore, the blocks having higher polarities among theblocks that constitute a block copolymer are seen as wetting asubstrate, and the blocks having lower polarities are seen as wettingthe interface with the air. Therefore, there are a variety of techniquesproposed to enable different types of blocks, each with distinctproperties, of a block copolymer wetting at the substrate sidesimultaneously, the most representative of all is to produce a neutralsurface to control the orientation. However, in one aspect of thepresent application, when the parameters below are properly controlled,a block polymer can be vertically oriented also on a substrate that hadnot been previously treated by any method, such as surfaceneutralization, that is well-known in the art to achieve verticalorientation. Also, in another aspect of the present application,vertical orientation as the above can be induced within a short timeover a large area through thermal annealing.

The block copolymer of one aspect of the present application can form afilm that produces an in-plane diffraction pattern on a hydrophobicsurface during grazing-incidence small-angle X-ray scattering (GISAXS).The above block copolymer can form a film that produces an in-planediffraction pattern on a hydrophilic surface during GISAXS.

In the present application, producing an in-plane diffraction patternduring GISAXS may refer to having peaks that are vertical to thex-component in a GISAXS diffraction pattern during GISAXS analysis. Suchpeaks are observed due to vertical orientation of a block copolymer.Therefore, a block copolymer producing an in-plane diffraction patternindicates vertical orientation. In another embodiment, the number of theaforementioned peaks that are observed on the x-component of a GISAXSdiffraction pattern may be at least 2, and when multiple peaks arepresent, the scattering vectors (q values) of the peaks may beidentified to have integer ratios, in which case, the phase separationefficiency of the block copolymer can be further improved.

In the present application, errors are accounted for in the term“vertical”; for example, the definition of this term may include anerror within the range of ±10 degrees, ±8 degrees, ±6 degrees, ±4degrees, or ±2 degrees.

The block copolymer capable of forming a film that produces an in-planediffraction pattern both on a hydrophilic surface and on a hydrophobicsurface can exhibit vertical orientation on a variety of surfaces thathad not been previously treated by any particular method to inducevertical orientation. In the present application, the term “ahydrophilic surface” refers to a surface whose wetting angle againstpurified water is in the range of 5 degrees to 20 degrees. Examples of ahydrophilic surface may include, but are not limited to, the surface ofsilicon that is surface-treated with oxygen plasma, sulfuric acid or apiranha solution. In the present application, the term “a hydrophobicsurface” refers to a surface whose room-temperature wetting angleagainst purified water is in the range of 50 degrees to 70 degrees.Examples of a hydrophobic surface may include, but are not limited to,the surface of polydimethylsiloxane (PDMS) that is surface-treated withoxygen plasma, the surface of silicon that is surface-treated withhexamethyldisilazane (HMDS), and the surface of silicon that issurface-treated with hydrogen fluoride (HF).

Unless specifically indicated otherwise, the properties (e.g. a wettingangle) that may change depending on the temperature in the presentapplication are numerical values that are measured at room temperature.The term “room temperature” refers to the temperature in its naturalstate, which has not undergone heating or cooling, and may refer to atemperature of about 10° C. to 30° C., about 25° C., or about 23° C.

The film that is formed on a hydrophilic or hydrophobic surface andproduces an in-plane diffraction pattern during GISAXS may be a filmthat has undergone thermal annealing. The film for a GISAXS measurementmay be formed, for example, by applying a solution—that is prepared bydissolving the above block copolymer at a concentration of about 0.7 wt% in a solvent (e.g. flourobenzene)—on the corresponding hydrophilic orhydrophobic surface at a thickness of about 25 nm and a coating area of2.25 cm² (width: 1.5 cm, length: 1.5 cm) and thermal-annealing thecoated layer. The thermal annealing may be carried out, for example, byallowing the above film to be maintained at a temperature of about 160°C. for about 1 hour. GISAXS may be measured by having an X-ray incidenton a film, which is prepared in the aforementioned manner, at an angleof incidence in the range of about 0.12 to 0.23 degrees. A diffractionpattern that is scattered from the film can be obtained by a measuringdevice (e.g. 2D marCCD) that is well-known in the art. The method ofusing the diffraction pattern to verify the presence or absence of anin-plane diffraction pattern is well-known in the art.

The block copolymer that is observed to have the aforementioned peaksduring GISAXS can exhibit an excellent self-assembling property, whichcan also be controlled effectively depending on the purpose.

The block copolymer of the present application can show at least onepeak within a predetermined scattering vector q range during X-raydiffraction (XRD) analysis.

For example, the above block copolymer may have at least one peak in thescattering vector q range of 0.5 nm⁻¹ to 10 nm⁻¹ during XRD analysis. Inanother embodiment, the scattering vector q at which the above peak(s)appear(s) may be 0.7 nm⁻¹ or more, 0.9 nm⁻¹ or more, 1.1 nm⁻¹ or more,1.3 nm⁻¹ or more, or 1.5 nm⁻¹ or more. Also, in another embodiment, thescattering vector q at which the above peak(s) appear(s) may be 9 nm⁻¹or less, 8 nm⁻¹ or less, 7 nm⁻¹ or less, 6 nm⁻¹ or less, 5 nm⁻¹ or less,4 nm⁻¹ or less, 3.5 nm⁻¹ or less, or 3 nm⁻¹ or less.

The full width at half maximum (FWHM) of the peak(s) that is/areobserved within the above scattering vector q range may be in the rangeof 0.2 to 0.9 nm⁻¹. In another embodiment, the above FWHM may be 0.25nm⁻¹ or more, 0.3 nm⁻¹ or more, or 0.4 nm⁻¹ or more. Also, in anotherembodiment, the above FWHM may be 0.85 nm⁻¹ or less, 0.8 nm⁻¹ or less,or 0.75 nm⁻¹ or less.

In the present application, the term “full width at half maximum” mayrefer to the width (i.e. the difference between the two extremescattering vector q values) of the largest peak at half the maximumamplitude.

The above scattering vector q and FWHM in XRD analysis are numericalvalues obtained by a numerical analytical method that appliesleast-squares regression on the XRD analytical result. In the abovemethod, the part that corresponds to the minimum intensity in an XRDdiffraction pattern is set as the baseline and the minimum intensity isset as zero, then the peak profile of the above XRD pattern is subjectto Gaussian fitting, and the aforementioned scattering vector q and FWHMare obtained from the fitted result. When the above Gaussian fitting isperformed, the R-square value is at least 0.9 or more, 0.92 or more,0.94 or more, or 0.96 or more. The method of obtaining the informationfrom XRD analysis, as mentioned above, is well-known in the art; forexample, a numerical analysis program, such as Origin, may be used.

The block copolymer that produces a peak that has the aforementionedFWHM value in the aforementioned scattering vector q range can have acrystalline region that is suitable for self-assembly. The blockcopolymer that is identified in the aforementioned scattering vector qrange can exhibit an excellent self-assembling property.

XRD analysis may be carried out by transmitting X-rays through a blockcopolymer specimen and then measuring the scattering intensity withrespect to a scattering vector. XRD analysis may be carried out on ablock copolymer without requiring any particular pretreatment; forexample, it may be conducted by drying the block copolymer under asuitable condition and then transmitting X-rays through it. An X-raywhose vertical size is 0.023 mm and horizontal size is 0.3 mm may beused. The scattering vector and FWHM may be obtained through theacquisition of the 2D diffraction pattern—that is scattered from thespecimen—in the form of an image by using a measuring device (e.g. 2DmarCCD) and the fitting of the acquired diffraction pattern in theaforementioned method.

When at least one of the blocks constituting a block copolymer containsthe aforementioned chain as will be described below in the presentspecification, the number n of the chain-forming atoms in the chain maysatisfy both the scattering vector q, which is obtained from theaforementioned XRD analysis, and the following Equation 1.

3 nm⁻¹ to 5 nm⁻¹ =nq/(2×π)  [Equation 1]

In Equation 1, n represents the number of the aforementionedchain-forming atoms, and q represents the smallest scattering vectorwhose peak is detectable, or the scattering vector that is observed tohave the peak with the largest peak area, during the XRD analysis on theabove block copolymer. In addition, π represents the ratio of thecircumference of a circle to its diameter in Equation 1.

The q and the like of Equation 1 are numerical values that are obtainedin the same manner as the description of the aforementioned XRD analysismethod.

The q of Equation 1 may be, for example, a scattering vector in therange of 0.5 nm⁻¹ to 10 nm⁻¹. In another embodiment, the q of Equation 1may be 0.7 nm⁻¹ or more, 0.9 nm⁻¹ or more, 1.1 nm⁻¹ or more, 1.3 nm⁻¹ ormore, or 1.5 nm⁻¹ or more. Also, in another embodiment, the q ofEquation 1 may be 9 nm⁻¹ or less, 8 nm⁻¹ or less, 7 nm⁻¹ or less, 6 nm⁻¹or less, 5 nm⁻¹ or less, 4 nm⁻¹ or less, 3.5 nm⁻¹ or less, or 3 nm⁻¹ orless.

Equation 1 describes the relationship between the distance D among theblocks (that contain the aforementioned chain) and the number ofchain-forming atoms, when the block copolymer is self-assembled to forma phase-separated structure. When the number of chain-forming atoms inthe block copolymer containing the aforementioned chain satisfiesEquation 1, the crystallinity of the chain increases, and thereby thephase separation or vertical orientation property can significantlyimprove. In another embodiment, nq/(2×π) in Equation 1 may be 4.5 nm⁻¹or less. In the above description, the distance (D, in the unit of nm)among the blocks containing the above chain can be calculated by usingthe equation, D=2×π/q, where D represents the above distance (D, in theunit of nm) among the blocks, and π and q are as defined in Equation 1.

In one aspect of the present application, the absolute value of thedifference between the surface energy of the block 1 and the surfaceenergy of the block 2 in a block copolymer may be 10 mN/m or less, 9mN/m or less, 8 mN/m or less, 7.5 mN/m or less, or 7 mN/m or less. Also,the absolute value of the difference between the above surface energiesmay be 1.5 mN/m, 2 mN/m, or 2.5 mN/m or more. The structure in which theblock 1 and block 2, which have an absolute value of the difference insurface energies in the above range, are connected to each other bycovalent bonds can induce microphase separation as the result of phaseseparation due to a sufficient level of immiscibility. In the abovedescription, the block 1 may be, for example, the aforementioned blockthat contains the aforementioned chain.

A surface energy may be measured by using the Drop Shape Analyzer DSA100(manufactured by KRUSS GmbH). Specifically, the surface energy may bemeasured on the film prepared by applying a coating solution—which isprepared by dissolving the subject specimen to be measured (i.e. a blockcopolymer or a homopolymer) in fluorobenzene to a solid concentration ofabout 2 wt %—on a substrate at a thickness of about 50 nm and a coatingarea of 4 cm² (width: 2 cm, length: 2 cm), drying at room temperaturefor about 1 hour, and then thermal-annealing at 160° C. for about 1hour. The process of measuring a contact angle by dropping deionizedwater, whose surface tension is well-known in the art, on the abovethermal-annealed film is repeated for 5 times, and the 5 measured valuesof a contact angle are averaged. Similarly, the process of measuring acontact angle by dropping diiodomethane, whose surface tension iswell-known in the art, on the above thermal-annealed film is repeatedfor 5 times, and the 5 measured values of a contact angle are averaged.Subsequently, the surface energies can be obtained by using the averagedvalues of the contact angle, which were measured respectively withdeionized water and diiodomethane, and substituting the numerical value(Strom value) that corresponds to the surface tension of a solvent intothe equations according to the Owens-Wendt-Rabel-Kaelble method. Thenumerical value that corresponds to the surface energy of each block ofa block copolymer can be obtained by using the above-described method ona homopolymer that is made up of only the monomer that constitutes theabove block.

In the case that the block copolymer contains the aforementioned chain,the block that contains the chain may have a higher surface energycompared to the other block. For example, when the block 1 of a blockcopolymer contains the above chain, the surface energy of the block 1may be higher than that of the block 2. In this case, the surface energyof the block 1 may be in the range of about 20 mN/m to 40 mN/m. Thesurface energy of the above block 1 may be 22 mN/m or more, 24 mN/m ormore, 26 mN/m or more, or 28 mN/m or more. Also, the surface energy ofthe above block 1 may be 38 mN/m or less, 36 mN/m or less, 34 mN/m orless, or 32 mN/m or less. The block copolymer in which the above block 1is contained and has a surface energy that is different from that of theblock 2 as described above can exhibit an excellent self-assemblingproperty.

In a block copolymer, the absolute value of the difference in densitiesbetween the block 1 and block 2 may be 0.25 g/cm³ or more, 0.3 g/cm³ ormore, 0.35 g/cm³ or more, 0.4 g/cm³ or more, or 0.45 g/cm³ or more. Theaforementioned absolute value of the difference in densities may be 0.9g/cm³ or more, 0.8 g/cm³ or less, 0.7 g/cm³ or less, 0.65 g/cm³ or less,or 0.6 g/cm³ or less. The structure in which the block 1 and block 2have the absolute value of the difference in densities within the aboverange and are connected to each other by covalent bonds may induceeffective microphase separation as the result of phase separation due toa sufficient level of immiscibility.

The density of each block in the above block copolymer can be measuredby using a buoyancy method that is well-known in the art; for example,the density can be measured by analyzing the mass of the block copolymerin a solvent, such as ethanol, whose mass and density in air are known.

When a block copolymer contains the aforementioned chain, the block inwhich the chain is contained may have a lower density compared to theother block(s). For example, when the block 1 of a block copolymercontains the aforementioned chain, the density of the block 1 may belower than that of the block 2. In this case, the density of the block 1may be in the range of about 0.9 g/cm³ to 1.5 g/cm³. The density of theabove block 1 may be 0.95 g/cm³ or more. The density of the above block1 may be 1.4 g/cm³ or less, 1.3 g/cm³ or less, 1.2 g/cm³ or less, 1.1g/cm³ or less, or 1.05 g/cm³ or less. The block copolymer in which theabove block 1 is contained and has a density that is different from thatof the block 2 as described above can exhibit an excellentself-assembling property. The aforementioned surface energy and densitymay be numerical values that are measured at room temperature.

A block copolymer may contain a block whose volume fraction is in therange of 0.4 to 0.8 and a block whose volume fraction is in the range of0.2 to 0.6. In the case that the block copolymer contains theaforementioned chain, the volume fraction of the block in which thechain is contained may be in the range of 0.4 to 0.8. For example, whenthe chain is contained in the block 1, the volume fraction of the block1 may be in the range of 0.4 to 0.8, and the volume fraction of theblock 2 may be in the range of 0.2 to 0.6. The sum of volume fractionsof the block 1 and block 2 may be equal to 1. The block copolymer thatcontains each block in the aforementioned volume fraction can exhibit anexcellent self-assembling property. The volume fraction of each block ina block copolymer can be obtained based on the density of the block plusthe molecular weight, which is measured by gel permeation chromatography(GPC).

The number average molecular weight (Mn) of a block copolymer may be,for example, in the range of 3,000 to 300,000. In the presentspecification, the term “number average molecular weight” refers to anumerical value that is measured with GPC and calibrated based on astandard polystyrene, and, unless specifically indicated otherwise, theterm “molecular weight” in the present specification refers to numberaverage molecular weight. In another embodiment, Mn may be, for example,3000 or more, 5000 or more, 7000 or more, 9000 or more, 11000 or more,13000 or more, or 15000 or more. In still another embodiment, Mn may beabout 250000 or less, 200000 or less, 180000 or less, 160000 or less,140000 or less, 120000 or less, 100000 or less, 90000 or less, 80000 orless, 70000 or less, 60000 or less, 50000 or less, 40000 or less, 30000or less, or 25000 or less. A block copolymer may have a polydispersity(Mw/Mn) in the range of 1.01 to 1.60. In another embodiment, the Mw/Mnmay be about 1.1 or more, about 1.2 or more, about 1.3 or more, or about1.4 or more.

In such a range, a block copolymer can exhibit a sufficientself-assembling property. The Mn and the like of a block copolymer canbe adjusted in consideration of the self-assembled structure of interestand the like.

In the case that the block copolymer contains at least theaforementioned block 1 and block 2, the proportion of the block 1 (e.g.the proportion of the block that contains the aforementioned chain) inthe above block copolymer may be in the range of 10 mol % to 90 mol %.

In the present application, there is no particular limitation to thedetailed method of preparing a block copolymer such as the above, aslong as the method includes forming at least one block of the blockcopolymer by using monomers that can form each of the aforementionedstructural unit.

For example, a block copolymer may be prepared in a living radicalpolymerization (LRP) method that makes use of the above monomers.Examples of the method include synthesis by anionic polymerization inwhich an organic rare-earth metal complex or organic alkali metalcompound is used as the polymerization initiator in the presence of analkali metal and an inorganic acid salt such as an alkaline earth metal;synthesis by an anionic polymerization method in which an organic alkalimetal compound is used as the polymerization initiator in the presenceof an organic aluminum compound; an atom transfer radical polymerization(ATRP) method in which an ATRP agent is used as thepolymerization-control agent; an activators regenerated by electrontransfer (ARGET) ATRP method in which an ATRP agent is used as thepolymerization-control agent but the polymerization takes place in thepresence of an organic or inorganic reducing agent that generates anelectron; an initiators for continuous activator regeneration (ICAR)ATRP method; polymerization by a reversible addition-fragmentation chaintransfer (RAFT) method in which an inorganic reducing agent and a RAFTagent are used; and a method of using an organic tellurium compound asthe initiator, among which a suitable method may be selected for use.

For example, the aforementioned block copolymer may be prepared throughpolymerization of a reactant (that includes the monomers capable offorming the aforementioned block) by a living radical polymerizationmethod in the presence of a radical initiator and a living radicalpolymerization reagent.

There is no particular limitation to the method of forming another blockto be contained in a block copolymer together with the block(s) formedof the aforementioned monomers during the preparation of the blockcopolymer; the monomer(s) may be suitably selected in consideration ofthe block type of interest for the formation of the other block.

The process of preparing a block copolymer may further include, forexample, precipitating, in a nonsolvent, the polymerization product thatis produced through the above processes.

There is no particular limitation to the type of the radical initiator,and the radical initiator may be suitably selected in consideration ofthe polymerization efficiency; for example, an azo compound such asazobisisobutyronitrile (AIBN) and2,2′-azobis-(2,4-dimethylvaleronitrile), or a peroxide series such asbenzoyl peroxide (BPO) and di-t-butyl peroxide (DTBP) may be used.

A living radical polymerization process may be carried out, for example,in a solvent such as methylene chloride, 1,2-dichloroethane,chlorobenzene, dichlorobenzene, benzene, toluene, acetone, chloroform,tetrahydrofuran, dioxane, monoglyme, diglyme, dimethylformamide,dimethyl sulfoxide, and dimethylacetamide.

Examples of a nonsolvent include, but are not limited to, an alcohol(such as methanol, ethanol, n-propanol, and isopropanol), a glycol (suchas ethylene glycol), n-hexane, cyclohexane, n-heptane, and an ether(such as petroleum ether).

The present application also relates to a polymer film that contains theaforementioned block copolymer. The polymer film may be used in avariety of applications, for example, in a variety of electronic orelectrical devices, in the process of forming the aforementionedpatterns, in magnetic storage recording media such as flash memory, orin biosensors.

In one embodiment, the aforementioned block copolymer may realize aregular structure, such as a sphere, a cylinder, a gyroid or a lamella,through self-assembly in the aforementioned polymer film.

For example, the block 1, the block 2 or (in the segment of the otherblock that is covalently bonded to any of the block 1 and block 2) thesegment may form a regular structure such as a lamella form or acylindrical form in a block copolymer.

The above polymer film in the present application may have an in-planediffraction pattern, which is a peak(s) vertical to the x-component of aGISAXS diffraction pattern, during GISAXS analysis. In anotherembodiment, the number of the peaks observed along the x-component ofthe above GISAXS diffraction pattern may be at least 2 and, when thereare multiple peaks present, the scattering vector q values of the peaksmay be observed to be in an integer ratio.

The aforementioned block 2 may form a crosslinked structure in a polymerfilm such as the above. That is, the crosslinked structure may beformed, for example, by a method of crosslinking the crosslinkablefunctional group of the structural unit of Structural Formula 5 in theabove block 2 in the presence of a self-assembled structure. In thiscase, the condition of forming a crosslinked structure is notparticularly limited and may be adjusted in consideration of the typeand amount of the crosslinkable functional group used. For example, whenthe above crosslinkable functional group is one among the aforementionedazide-containing functional group, the crosslinking may be conducted byallowing a self-assembled block copolymer to be maintained at atemperature of about 200° C. to 230° C. for about 30 minutes to 1 hour.

The present application also relates to a method of forming a polymerfilm by using the aforementioned block copolymer. The method may includeforming a polymer film containing the above block copolymer on asubstrate in a self-assembled state. For example, the above method mayinclude forming a layer of the above block copolymer or a layer of acoating solution in which the block copolymer is dissolved in a suitablesolvent, on a substrate by deposition or the like, and, if needed, itmay also include a process of annealing or heat-treating the abovelayer.

The above annealing or heat-treating (heat-treatment) may be carriedout, for example, based on the phase transition temperature or glasstransition temperature of the block copolymer; for example, it may becarried out at a temperature equal to or greater than the above glasstransition temperature or phase transition temperature. The duration ofsuch a heat-treatment is not particularly limited and may be, forexample, in the range of about 1 minute to 72 hours, although it may besubject to change as necessary. Also, the heat-treatment temperature ofa polymer thin film may be, for example, about 100° C. to 250° C., whichmay be subject to change depending on the block copolymer to be used.

In another embodiment, the layer that is formed as the above may besolvent-annealed in a room-temperature nonpolar solvent and/or polarsolvent for about 1 minute to 72 hours.

The process of crosslinking the above block 2 may be additionallyconducted after a polymer film is formed as the above. Such acrosslinking is processed as described above in the presentspecification.

The present application also relates to a method of forming a pattern.The above method may include, for example, a process of selectivelyremoving the block 1 or block 2 of a block copolymer from the laminatethat is made up of a substrate and a polymer film, which is formed onthe substrate and contains the above self-assembled block copolymer. Theabove method may be a method of forming a pattern on the abovesubstrate. For example, the above method may include forming, on asubstrate, a polymer film that contains the above block copolymer,selectively removing any one or more blocks of the block copolymer thatis present in the above film, and subsequently etching the substrate.The above method enables the formation of a micropattern, for example,in nanoscale. Also, a variety of patterns such as a nanorod and ananohole may be formed by the above method, depending on the structureof the block copolymer in the polymer film. If needed, the above blockcopolymer may be mixed with another copolymer, a homopolymer or the likefor the formation of patterns. The type of the substrate to be appliedin the above method is not particularly limited and may be selected tosuit the application; for example, silicon oxide may be used.

The aforementioned block 2 in a polymer film used in the process ofselectively removing the above block 1 and/or block 2 may contain acrosslinked structure, where the method of realizing the crosslinkedstructure is as described above in the present specification.

For example, the above method may form a silicon-oxide nanoscale patternthat exhibits a high aspect ratio. A variety of forms such as a nanorodand a nanohole may be realized, for example, by forming the abovepolymer film on the silicon oxide, selectively removing any one block ofa block copolymer in the above polymer film where the block copolymerconstitutes a predetermined structure, and then etching the siliconoxide by any one of various techniques, for example, by reactive-ionetching. Also, the above method may enable the realization of ananopattern having a high aspect ratio.

For example, the above pattern may be realized in the scale of tens ofnanometers, and such a pattern may be used for a variety of applicationsincluding, for example, magnetic recording media for the next-generationinformation and electronics.

For example, a pattern in which nanostructures (e.g. nanowires) whosewidth is about 3 nm to 40 nm are arranged spaced apart (e.g. by 6 nm to80 nm) can be formed by the above method. In another embodiment, astructure in which nanoholes whose width (e.g. diameter) is about 3 nmto 40 nm are arranged spaced apart by about 6 nm to 80 nm can also berealized.

In addition, the nanowires or nanoholes in the above structure can bemade to have high aspect ratios.

In the above method, there is no particular limitation to the method ofselectively removing any one block of a block copolymer; for example, amethod of removing a relatively soft block by having the polymer filmirradiated with suitable electromagnetic waves such as ultraviolet raysmay be used. In this case, the condition of an ultraviolet rayirradiation is determined by the type of blocks in the block copolymer;for example, it may include an irradiation of the ultraviolet rays whosewavelength is about 254 nm for 1 minute to 60 minutes.

In addition, following the ultraviolet ray irradiation, the process ofadditionally removing the segment that was previously disintegrated byultraviolet rays may be carried out by treating the polymer film with anacid or the like.

In addition, there is no particular limitation to the process of etchingthe substrate by using, as the mask, the polymer film that has beenselectively removed of certain blocks; for example, the above etchingmay be carried out through reactive-ion etching with CF₄/Ar ions or thelike. The above etching may be followed by the process of removing thepolymer film from the substrate through an oxygen plasma treatment orthe like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a SEM image of a polymer layer that is formed by using a blockcopolymer of Example 1 and that is before a photo crosslinking.

FIG. 2 is a SEM image of a polymer layer that is formed by using a blockcopolymer of Example 1 and that is after a photo crosslinking.

FIG. 3 shows a result after subjecting a polymer layer formed by using ablock copolymer of Example 1 to a solvent washing without a photocrosslinking.

EFFECT

The present application can provide a block copolymer and uses thereof.The block copolymer of the present application exhibits an excellentself-assembling property or phase separation property, can be providedwith a variety of required functions without constraint and, especially,etching selectivity can be secured, making the block copolymereffectively applicable to such uses as pattern formation.

DETAILED DESCRIPTION OF EMBODIMENTS

The present application is described in more detail hereinafter throughexamples according to the present application, but the scope of thepresent application is not limited to the examples which are proposedhereinafter.

1. NMR Measurement

NMR analysis was carried out at room temperature by using a NMRspectrometer that includes a Varian Unity Inova (500 MHz) spectrometerwith a 5-mm triple resonance probe. The analysis subject material wasdiluted with a solvent (CDCl₃) for an NMR measurement to a concentrationof about 10 mg/ml for use, and the chemical shift was expressed in ppm.

<Applied Abbreviations>

br=broad signal, s=singlet, d=doublet, dd=doublet of doublets,t=triplet, dt=doublet of triplets, q=quartet, p=quintet, m=multiplet.

2. Gel Permeation Chromatography (GPC)

The number average molecular weight (Mn) and molecular weightdistribution were measured by GPC. The analysis subject material such asa macroinitiator or the block copolymer of the examples was put in a5-mL vial and diluted with tetrahydrofuran (THF) to a concentration ofabout 1 mg/mL. Then, a standard specimen for calibration and thespecimen to be analyzed were filtered with a syringe filter (pore size:0.45 μm) and subsequently analyzed. ChemStation (Agilent TechnologiesInc.) was used as the analytical program, each of the weight averagemolecular weight (Mw) and Mn was obtained by comparing the elution timeof the specimen with the calibration curve, and then a molecular weightdistribution (polydispersity index, PDI) was calculated as a ratio(Mw/Mn). The measuring condition of GPC is as follows:

<GPC Measuring Conditions>

Device: 1200 Series of Agilent Technologies Inc.

Column: Two PLgel MIXED-B of Polymer Laboratories

Solvent: THF

Column temperature: 35° C.

Sample concentration: 1 mg/mL, 200 L is injected

Standard specimen: polystyrene (Mp: 3900000, 723000, 316500, 52200,31400, 7200, 3940, 485)

Preparation Example 1

The compound (DPM-C12) represented by the following Structural Formula Awas synthesized by the following method: hydroquinone (10.0 g, 94.2mmol) and 1-bromododecane (23.5 g, 94.2 mmol) were introduced into a250-mL flask, dissolved in 100 mL of acetonitrile; then, an excessiveamount of potassium carbonate was added to the above solution andallowed to react at about 75° C. for about 48 hours under a nitrogenatmosphere; upon completion of the reaction, the reaction products wereremoved of the remaining potassium carbonate and of acetonitrile thatwas used for the reaction; then the substances were worked up through anaddition of a mixed solvent of dichloromethane (DCM) and water, and theseparated organic layer was dehydrated with MgSO₄; subsequently, thesubstances were purified by column chromatography (CC) with DCM toobtain a white solid intermediate with a yield of about 37%.

<NMR Analysis Results of Intermediate>

¹H-NMR (CDCl₃): δ6.77 (dd, 4H); δ4.45 (s, 1H); δ3.89 (t, 2H); δ1.75 (p,2H); δ1.43 (p, 2H); δ1.33-1.26 (m, 16H); δ0.88 (t, 3H).

The synthesized intermediate (9.8 g, 35.2 mmol), methacrylic acid (6.0g, 69.7 mmol), dicyclohexylcarbodiimide (DCC) (10.8 g, 52.3 mmol) andp-dimethylaminopyridine (DMAP) (1.7 g, 13.9 mmol) were introduced into aflask, 120 mL of methylene chloride was added, and then allowed to reactat room temperature for 24 hours under a nitrogen atmosphere; uponcompletion of the reaction, the reaction products were filtered to beremoved of a urea salt that was produced during the reaction and also ofthe remaining methylene chloride; then, the substances were removed ofimpurities by column chromatography (CC) that uses hexane anddichloromethane (DCM) as the mobile phase, the obtained products wererecrystallized in a mixed solvent of methanol and water (mixed at aweight ratio of 1:1) to obtain a white solid target material (DPM-C12)(7.7 g, 22.2 mmol) with a yield of 63%.

<NMR Analysis Results of DPM-C12>

¹H-NMR (CDCl₃): δ7.02 (dd, 2H); δ6.89 (dd, 2H); δ6.32 (dt, 1H); δ5.73(dt, 1H); δ3.94 (t, 2H); δ2.05 (dd, 3H); δ1.76 (p, 2H); δ1.43 (p, 2H);1.34-1.27 (m, 16H); δ0.88 (t, 3H).

In Structural Formula A, R represents a linear-chain alkyl group with 12carbons.

Preparation Example 2

3-hydroxy-1,2,4,5-tetrafluorostyrene was synthesized by the followingmethod. Pentafluorostyrene (25 g, 129 mmol) was added to a mixedsolution of 400 mL of tert-butanol and potassium hydroxide (37.5 g, 161mmol) and then reacted for 2 hours (reflux reaction). After cooling thereacted product to room temperature, 1200 mL of water was added theretoand remained butanol used for the reaction was eliminated viavolatilization. The reacted product was extracted 3 times by diethylether (300 mL); the target materials were precipitated by acidifying theaqueous solution layer with a 10-weight % hydrochloric acid solution toa pH of about 3; and then the organic layer was collected by extracting3 times by diethyl ether (300 mL).

The organic layer was then dehydrated with MgSO₄ and solvent was removedso as to obtain crude product. The crude product was purified by columnchromatography by using hexane and dichloromethane (DCM) as the mobilephase to acquire colorless liquid 3-hydroxy-1,2,4,5-tetrafluorostyrene(11.4 g). The results of NMR analysis on the above substance are asfollows.

<NMR Analysis Results>

¹H-NMR (DMSO-d): δ11.7 (s, 1H); δ6.60 (dd, 1H); δ5.89 (d, 1H); δ5.62 (d,1H)

The compound of the chemical formula B below was synthesized by thefollowing method. The obtained intermediate(3-hydroxy-1,2,4,5-tetrafluorostyrene) (1.7 g, 7.8 mmol),4-benzoylbenzoic acid (1.9 g, 8.6 mmol), DCC (dicyclohexylcarbodiimide)(1.8 g, 8.6 mmol) and DMPA (p-dimethylaminopyridine) (0.48 g, 3.1 mmol)were mixed and 30 mL of methylene chloride was added thereto and thenthe mixture was reacted under nitrogen at room temperature for 24 hours.After the termination of the reaction, urea salt produced during thereaction and remained methylene chloride were eliminated. Impuritieswere eliminated in a column chromatography using hexane and DCM(dichloromethane) as a mobile phase and then the obtained product wasrecrystallized in mixed solvent of methanol and water(methanol:water=3:1 (weight ratio)) so as to obtain white solid targetmaterial that was the monomer of the chemical formula B with a yield of70 weight %.

The results of NMR analysis on the above compound is as follows.

<NMR Analysis Results>

¹H-NMR (CDCl₃): δ8.3 (t, 2H); δ7.9 (q, 2H); δ7.8 (d, 2H); δ7.6 (t, 2H);δ7.5 (dd, 2H); δ6.60 (dd, 1H); δ5.89 (d, 1H); δ5.62 (d, 1H);

Example 1

2.0 g of the compound (DPM-C12) of Preparation Example 1, 64 mg of areversible addition-fragmentation chain transfer (RAFT) reagent(2-cyano-2-propyl dodecyl trihiobenzoate), 23 mg of AIBN(azobisisobutyronitrile) and 5.34 mL of anisole were put into a 10 mLSchlenk flask, and stirred at room temperature for 30 minutes under anitrogen atmosphere to allow an RAFT polymerization reaction at 70° C.for 4 hours. After the polymerization, a reaction solution wasprecipitated in 250 ml of methanol as an extraction solvent, and driedthrough decreased pressure filtration, thereby preparing a primrosemacroinitiator. The yield of the macroinitiator was about 80 weight %,and the number average molecular weight (Mn) and distribution ofmolecular weight (Mw/Mn) of the macroinitiator were 6100 and 1.25,respectively.

0.2 g of the obtained macroinitiator, 3.589 g of pentafluorostyrene and0.151 g of the photo crosslinkable monomer of the structural formula Bof Preparation Example 2 and 1.697 mL of anisole were put into a 10 mLSchlenk flask, and stirred at room temperature for 30 minutes under anitrogen atmosphere to allow an RAFT polymerization reaction at 70° C.for 3 hours. After the polymerization, a reaction solution wasprecipitated in 250 ml of methanol as an extraction solvent, and driedthrough decreased pressure filtration, thereby preparing a light yellowblock copolymer. The yield of the block copolymer was about 14 weight %,and the number average molecular weight (Mn) and distribution ofmolecular weight (Mw/Mn) of the block copolymer were 14,400 and 1.21,respectively. The block copolymer includes a first block derived fromthe compound (DPM-C12) of Preparation Example 1 and a second blockderived from the pentafluorostyrene and the compound of the structuralformula B in Preparation Example 2.

Test Example 1

A self-assembled polymer film was formed by using the block copolymerthat was synthesized in Example 1, and the results were observed. Theprepared block copolymer was dissolved in a solvent to a concentrationof 1.0 weight %; then spin-coated on a silicon wafer for about 60seconds at a speed of about 3000 rpm and then was subjected to a thermalannealing so as to form a polymer thin film including self assembledblock copolymer. FIG. 1 is a SEM image of the obtained polymer thinfilm. Then the polymer thin film was irradiated with ultraviolet ray.The ultraviolet ray having a wavelength of about 254 nm was irradiatedwith light intensity of about 2 J/cm². FIG. 2 is a SEM image of thepolymer thin film after the above photocrosslinking. As a result ofperforming solvent washing to the polymer thin film, it was confirmedthat the selective etching can be performed.

FIG. 3 shows the result after performing the solvent washing withrespect to a polymer thin film before photo crosslinking process and itcan be confirmed from FIG. 3 that the etching selectivity between blockscannot be obtained.

What is claimed is:
 1. A block copolymer comprising a first blockcomprising a unit represented by Structural Formula 1 below and a secondblock comprising a unit represented by Structural Formula 3 below:

wherein, R of the Formula 1 represents a hydrogen atom or an alkylgroup; X of the Formula 1 represents a single bond, an oxygen atom, asulfur atom, —S(═O)₂—, a carbonyl group, an alkylene group, analkenylene group, an alkynylene group, —C(═O)—X₁— or —X₁—C(═O)—, whereinthe X₁ represents an oxygen atom, a sulfur atom, —S(═O)₂—, an alkylenegroup, an alkenylene group or an alkynylene group; Y of the Formula 1represents a monovalent substituent that includes a ring structure towhich a linear chain including 8 or more chain-forming atoms isconnected; and X₂ of the Formula 3 represents a single bond, an oxygenatom, a sulfur atom, —S(═O)₂—, an alkylene group, an alkenylene group,an alkynylene group, —C(═O)—X₂— or —X₂—C(═O)—, wherein the X₂ representsa single bond, an oxygen atom, a sulfur atom, —S(═O)₂—, an alkylenegroup, an alkenylene group or an alkynylene group; and each of R₁ to R₅of the Formula 3 independently represents a hydrogen atom, an alkylgroup, a haloalkyl group, a halogen atom or a photo crosslinkablefunctional group, wherein one or more of the photo crosslinkablefunctional groups are included in positions marked as R₁ to R₅.
 2. Theblock copolymer of claim 1, wherein the X represents a single bond, anoxygen atom, a carbonyl group, —C(═O)—O—, or —O—C(═O)—.
 3. The blockcopolymer of claim 1, wherein the linear chain includes 8 to 20chain-forming atoms.
 4. The block copolymer of claim 1, wherein thechain-forming atom is carbon, oxygen, nitrogen, or sulfur.
 5. The blockcopolymer of claim 1, wherein the chain-forming atom is carbon oroxygen.
 6. The block copolymer of claim 1, wherein the ring structure ofthe Y is an aromatic ring structure or an alicyclic ring structure. 7.The block copolymer of claim 1, wherein the Y of the Structural Formula1 is represented by Structural Formula 2 below:—P-Q-Z  [Structural Formula 2] where in the Structural Formula 2, Prepresents an arylene group; Q represents a single bond, an oxygen atomor —NR₃—, wherein the R₃ represents a hydrogen atom, an alkyl group, analkenyl group, an alkynyl group, an alkoxy group or an aryl group; and Zrepresents a linear chain with 8 or more chain-forming atoms.
 8. Theblock copolymer of claim 1, wherein the photo crosslinkable functionalgroup is benzoylphenoxy group, alkenyloxycarbonyl group, (meth)acryloylgroup or alkenyloxyalkyl group.
 9. The block copolymer of claim 1,wherein one or more halogen atoms are included in the positions markedas R₁ to R₅ of the Structural Formula
 3. 10. The block copolymer ofclaim 1, wherein a ratio of the unit represented by the structuralformula 3 in the second block is from 0.1 mol % to 5 mol %.
 11. Theblock copolymer of claim 1, wherein the second block further includes astructural unit represented by Structural Formula 4 below:

where in the Structural Formula 4, X₂ represents a single bond, anoxygen atom, a sulfur atom, —S(═O)₂—, an alkylene group, an alkenylenegroup, an alkynylene group, —C(═O)—X₁— or —X₁—C(═O)—, wherein the X₁represents a single bond, an oxygen atom, a sulfur atom, —S(═O)₂—, analkylene group, an alkenylene group or an alkynylene group; and Wrepresents an aryl group that includes at least one halogen atom. 12.The block copolymer of claim 1, wherein the second block furtherincludes a structural unit represented by Structural Formula 5 below:

where in the Structural Formula 5, X₃ represents a single bond, anoxygen atom, a sulfur atom, —S(═O)₂—, an alkylene group, an alkenylenegroup, an alkynylene group, —C(═O)—X₁— or —X₁—C(═O)—, wherein the X₁represents a single bond, an oxygen atom, a sulfur atom, —S(═O)₂—, analkylene group, an alkenylene group or an alkynylene group; and each ofR_(a) to R_(e) independently represents a hydrogen atom, an alkyl group,a haloalkyl group or a halogen atom, wherein one or more halogen atomsare included in positions marked as R_(a) to R_(e).
 13. The blockcopolymer of claim 12, wherein 3 or more halogen atoms are included inthe positions marked as R_(a) to R_(e).
 14. The block copolymer of claim12, wherein 5 or more halogen atoms are included in the positions markedas R_(a) to R_(e).
 15. The block copolymer of claim 12, wherein thehalogen atom is a fluorine atom.
 16. A polymer film comprising the blockcopolymer of claim 1, wherein the block copolymer is self-assembled. 17.The polymer film of claim 16, wherein the second block of the blockcopolymer includes a crosslinked structure.
 18. A method of forming apolymer film, the method comprising: forming a polymer film thatincludes the block copolymer of claim 1 on a substrate, wherein theblock copolymer is self-assembled.
 19. The method of claim 18, furthercomprising: crosslinking of the second block of the block copolymer,wherein the block copolymer is self-assembled.
 20. A method of forming apattern, the method comprising: selectively removing any one block ofthe block copolymer of claim 1 from a laminate that is made up of asubstrate and a polymer film, which is formed on the substrate andincludes the block copolymer, wherein the block copolymer isself-assembled.
 21. The polymer film of claim 20, wherein the secondblock of the block copolymer includes a crosslinked structure.